Sound attenuating door and panel construction



May 16, 1967 H. w. WEHE, JR 3, 3

SOUND ATTENUATING DOOR AND PANEL CONSTRUCTION 8, 1966 I 2 Sheets-Sheet l M R x P,

3 1 9 T V E f Filed Sept.

INVENTOR HERBERT W WEHF. JR.

BY M1 245; m

ATTO RNEYS 2 Sheets-Sheet 2 d a D 4|! 0 d .iiliilllillilllvliirlliilllifl p Y 1 4 2 SOUND ATTENUATING DOOR AND PANEL CONSTRUCTION Ill/I May 16, 1967 Filed Sept.

INVENTOR. HERBERT W WEHE. JR.

BY M fAMAZ-b" ATTORNEYS United States Patent Oflice 3,319,738 Patented May 16, 1967 3,319,738 SOUND ATTENUATING DOOR AND PANEL CONSTRUCTION Herbert W. W'ehe, Jr., Ligonier, Pai, assignor to Overly Manufacturing Company Filed Sept. 8, 1966, Ser. No. 578,026 9 Claims. (Cl. Isl-33) This application is a continuation-in-par-t of my copending application Ser. No. 286,289 filed June 7, 1963, now Patent No. 3,273,297, issued Sept. 20, 1-966.

The present invention is concerned with sound attenuating doors and panels and more particularly with metal doors of the order of 1% to 2" thick employing a sound barrier referred to as a septum. Sound attenuating or acoustical doors of substantial thickness of the order 'of 6 inches and more are known in the art, but prior to my prior application Ser. No. 286,289 no door of the order of 1% thick had not ben produced having a large sound transmission loss of the order of 45 to 50 under testing procedures set up by The American Society for Testing Materials, designation E90-61T, Tentatively Recommended Practice for Laboratory Measurements of Airborne Sound Transmission Loss of Building Floor and Walls."

The exemplification of the invention is illustrated by a door ofthe type known in the trade 'as a flush type door as employed in offices and other commercial building to suppress passage of noises therethrough within the sound frequencies of 125 and 1400 cycles per second, such as normal conversation and business machine noises. Such doors are customarily mounted within metal door frames, with some clearance or space between the door and frame, and employ some form of a door seal. A preferred from of composite seal as shown, forming no part of the pres- 'ent invention, is described and claimed'in -U.S. Patent 3,221,376 granted December 7, 1965.

One object of the invention is to provide a septum type acoustical door having an improved form of septum.

This and other objects of the invention will be made apparent from the following description and the drawing forming a part thereof wherein a FIG.1 1. shows an elevation of the door and mounting frame;

FIG. 2 shows a horizontal section taken on lines II of FIG. 1;

FIG. 3 shows a vertical section taken on lines III-III of FIG. 1;

FIG. 4 shows a FIG. 3; and 1 4 FIG. 5 shows a modified form of door of FIG. 4 as modified to accommodate an automatic door seal as illustrated in FIG. 3; and

FIG. 6 shows a modified form of the septum of FIG. 4.

Referring now in detail to FIGS. 1 to 3 inclusive, the door frame indicated generally as F is of a more or less conventional design, preferably integral, and comprising metal side walls connected by metal top and bottom walls as shown and forms no part of the present invention. The door 1 pivotally mounted within the door frame, is preferably of metal having vertically disposed spaced front and rear walls 2 and 3 connected at their vertical margins by side walls 4 and 5. The walls 2 and 5 may be connected together in any suitable manner, preferably by providing opposing flanges on the walls 2 and 3 which are connected together, as by welds 6. Front and rear walls 2 and 3 are provided upon their inner faces with substantially Z-shaped reinforcing or stiffening members 7 and 8 respectively. Preferably members 7 and 8 are arranged in staggered relation as shown in FIG. 2. One flange of each member 7 and 8 abuts the adjacent walls modified form of the door shown in 2 or 3 and may be connected thereto in any suitable manher, as by suitably spaced spot welds 9. customarily the side wall 4 and 5 of the door are suitably reinforced at the hinge and door lock by suitable members 13 and 14, as shown.

Within door 1 are a pair of spaced spectum members, indicated generally at 10, comprised of a sheet of lead 11, preferably having on one face thereof a layer of foam rubber 12. The lead and foam rubber may be attached together by any suitable means, such as a commercially available contact adhesive. The lead sheet 11 and foam rubber 12 may be of any suitable thickness, 1 have found that sheet lead of about thick weighing about 2 lbs. per sq. ft. and foam rubber of about 4; thick give excellent results. The composite lead and foam rubber septums 10 are disposed across the flanges of stiffeners 7 and 8, preferably with the foam rubber portion 12 engaging the stiifeners. Intermediate the opposing lead faces of the septums is a layer of suitable porous material P such as Rockwool and between the foam rubber backing and the metal door sheets are similar layers of porous material P. Commercial Rockwool of 9 lb. density has been found to provide good results, other suitable materials may be used.

As best shown in FIG. 3, the upper and lower horizontal edges of the door are suitably closed, with the design of closure member governed by the type of door seals to be employed therewith. It being understood that a hinge mounted door must have suitable clearance at the door frame to swing freely. As shown in FIG. 3 the bottom of the door is spaced above the door frame sill member 15 a suitable distance for mounting any conventional type automatic drop sealing member 16 and/or 16a. Here the bottom face of the door is closed by a suitable longitudinally extending inverted U-shaped member 17 which may be attached to door plates 2 and 3, by any suitable means, including spot welding 18. Within 517 may be mounted any suitable housing member 19, attached to member 17 by suitable means, including spot welding 19. Within housing member 19 may be mounted any suitable automatic drop door seal 16. Upon the inner face 3 of the door, adjacent the bottom thereof may be mounted any suitable housing 20 for a second automatic drop door seal 16a if desired. The top horizontal face of door 1, may be provided with a longitudinally extending U-shaped member 21 suitably attached to the. door plates 2 and 3 by any suitable means, including welding. The bottom wall of member 21 may be suitably slotted to receive at least the spaced lead sheets 11 and the rockwool therebetween. A suitable inverted U-shaped member 22 having a perforated top wall 23 may be employed to close the top edge of the door and enclose the upper ends of the lead sheets 11. Suitably rockwool may be disposed between the depending arms of member 22 and the ends of the lead sheets 11. The perforated wall 23 permits portions of sound energy within the space between member 22 and the door frame to enter the door and thus relieve pressure on the door seal member S.

A more conventional form of closure for the top and bottom longitudinal surfaces of the door 1 is shown in FIG. 4 wherein the top and bottom horizontal faces of the door are formed by opposing inturned flanges 24 and 25 on door plates 2a and 3a which are connected by a suitable weld connection 26. The plate stiffeners 7a and 8a are attached to door plates 2a and 3a in any suitable mauner, including spot welding, and terminate in suitable spaced relation to flanges 24 and 25. The septums 10a and rockwool fillings P are applied as in FIGS. 2 and 3. In this modification a door seal S may be applied as shown on FIG. 2 and disposed longitudinally of the top and both sides of the door. No provision is made for a drop seal on the bottom of the door of FIG. 4. Where desired the door seals may be omitted entirely. As shown in FIG. 5, the bottom of the door of FIG. 4 may be modified to accommodate a drop seal such as 16 of FIG. 3. To effect this latter modification, the door plates 2b and 3b may be modified as shown, the door plate stiffeners 7b and 8b shortened and an inverted U-shaped member 17b welded between door plates 2b and 3b to accommodate a drop seal 16 as shOWn in FIG. 2. Additionally, seals S may be employed with the door of FIG. 5 as indicated in FIGS. 2 and 3. The top portion of the door of FIG. 5 may be as shown in FIG. 3 or 4.

A further modification of the invention is shown on FIG. 6 of the drawing. In FIG. 6 the door plates 2b and 3b are similar to door plates 20: and 3a of FIG. 4 as are the door plate stiifeners 7 and 8. A different form of septum 10a is shown which differs from the septum of FIG. 4, in that a single lead sheet 11a is employed and foam rubber backing 12a is applied to both faces of lead sheet 11a. The lead and backing members may be secured together by any suitable adhesive as on FIGS. 2 and 4. By way of illustration and not limitation the lead sheet of FIG. 6 may be as much as A3" thick and the foam rubber backing on opposite faces thereof may be as much as thick. However, either or both, the lead sheet and the foam rubber backing may be of greater or lesser thickness. The ro ckwool filling the space between each face of the septum and the door sheets may be of suitable density, such as in FIGS. 2 to 5. The top and bottom horizontal closure members of the door plates may be as shown in any of the FIGS. 2 through 5.

The term septum, or limp septum, as employed herein is to distinguish .over a rigid septum of the type which may vibrate and thus transfer sound from one face to the opposite face. Sheet lead, instead of lead impregnated vinyl as employed in my prior patent application S.N. 286,289, has the advantage of being semi-rigid.

Having described the invention and the presently best known mode of practicing same, it will be understood that the use of dimensions are by way of illustration and not limitation and obvious modifications apparent to those skilled in the art are to be measured by the scope of the appended claims.

I claim:

1. In a sound attenuating panel member for use as door and wall partitions, in combination spaced front and rear panel face plates having secured to the inner opposing surfaces thereof stiffening members terminating in spaced relation to the inner face of the opposite panel,

a septum member extending transversely of each said front and rear panel face plates and in abutting engagement with the said stiffening members thereon,

means connecting the adjacent peripheral edges of said front and rear panel face plates, and

a filling of sound pervious material between the opposing faces of said septums and between the opposite face of each septum and the adjacent inner face of said panel member.

2. The panel member as defined in claim 1 wherein the said means connecting the adjacent panel peripheral edges of at least one margin of the panel has perforations therein admitting sound to said sound pervious filling material. 3. The panel member as defined in claim 1, wherein said stiffening members of one face plate are disposed 5 in staggered relation to the stiffening members of the opposite face plate.

4. The panel member as defined in claim 1, wherein each said septum member comprises a non-porous semi-flexible face portion and a flexible compressible backing portion abutting the adjacent panel stiffening members.

5. The panel as defined in claim 4 wherein said semifiexible face portion is comprised of a lead sheet and the backing portion thereof is comprised of a non-rigid foam type material including foam rubber.

6. The panel as defined in claim 5, wherein said septum backing portion is of greater thickness than said semifiexible face portion.

7. The panel as defined in claim 5, wherein said septum semi-flexible face portion is comprised of sheet lead of about inch thick.

. '8. In a sound attenuating panel member for use as door and wall partitions, in combination spaced front and rear panel face plates having secured to the inner opposing surfaces thereof stiffening members terminating in spaced relation to the inner face of the opposite panel,

a septum member extending transversely of said front and rear panel face plates between the opposing faces of said stiffening members thereon and comprising a relative thin lead sheet having on the opposite faces thereof layers of non-metallic material spacing the septum from said stiffening members,

means connecting the adjacent peripheral edges of said front and rear panel face plates, and

sound pervious material filling the space between each face of the septum and the adjacent inner faces of said panel face plates.

9. The sound attenuating door as defined in claim 8, wherein said septum comprises a sheet of lead about ,4 thick and the non-metallic backing material is foam rubber of greater thickness than the lead sheet.

References Cited by the Examiner UNITED STATES PATENTS FOREIGN PATENTS 12/ 1948 Great Britain. 4/1966 Great Britain.

RICHARD B. WILKINSON, Primary Examiner.

R. S. WARD, Assistant Examiner. 

1. IN A SOUND ATTENUATING PANEL MEMBER FOR USE AS DOOR AND WALL PARTITIONS, IN COMBINATION SPACED FRONT AND REAR PANEL FACE PLATES HAVING SECURED TO THE INNER OPPOSING SURFACES THEREOF STIFFENING MEMBERS TERMINATING IN SPACED RELATION TO THE INNER FACE OF THE OPPOSITE PANEL, A SEPTUM MEMBER EXTENDING TRANSVERSELY OF EACH SAID FRONT AND REAR PANEL FACE PLATES AND IN ABUTTING ENGAGEMENT WITH THE SAID STIFFENING MEMBERS THEREON, MEANS CONNECTING THE ADJACENT PERIPHERAL EDGES OF SAID FRONT AND REAR PANEL FACE PLATES, AND A FILLING OF SOUND PERVIOUS MATERIAL BETWEEN THE OPPOSING FACES OF SAID SEPTUMS AND BETWEEN THE OPPOSITE FACE OF EACH SEPTUM AND THE ADJACENT INNER FACE OF SAID PANEL MEMBER. 